Prior to the present invention circuits that detect hook status and ringing generally used numerous components, including several opto-isolators to isolate the circuit. One opto-isolator detected ringing, while a second opto-isolator detected hook status. These opto-isolators created several problems, including increased cost, additional space requirements, and difficulty to remain in compliance with all regulations. Additionally, opto-isolators cannot be integrated into an ASIC (Application Specific Integrate Circuit) limiting the ability of cost and size reduction.
Therefore, it is the objective of the present invention to provide a simple circuit that can detect the status of an attached telephone line.